9VAC5-30-80: Lead

A. The primary and secondary ambient air quality standard for lead and its compounds is 1.5 micrograms per cubic meter, maximum arithmetic mean averaged over a calendar quarter, measured as elemental lead by a reference method based on Appendix G of 40 CFR Part 50, or by an equivalent method.

B. The standards set forth in subsection A of this section shall remain applicable to all areas notwithstanding the ambient air quality standard in subsection C of this section. The lead standard set forth in subsection A of this section shall no longer apply to an area one year after the effective date of the designation of that area, pursuant to § 107 of the federal Clean Air Act, for the lead ambient air quality standard set forth in subsection C of this section.

C. The primary and secondary ambient air quality standard for lead and its compounds is 0.15 micrograms per cubic meter, maximum arithmetic mean averaged over a three-month period, measured as lead either by (i) a reference method based on Appendix G of 40 CFR Part 50 and designated in accordance with 40 CFR Part 53; or (ii) an equivalent method designated in accordance with 40 CFR Part 53. The primary and secondary ambient air quality standards for lead are met when the maximum arithmetic three-month mean concentration for a three-year period, as determined in accordance with Appendix R of 40 CFR Part 50, is less than or equal to 0.15 micrograms per cubic meter.